Can allele-specific loop-mediated isothermal amplification be used for rapid detection of target-site herbicide resistance in Lolium spp.?

Background: Herbicide resistance is one of the threats to modern agriculture and its early detection is one of the most effective components for sustainable resistance management strategies. Many techniques have been used for target-site-resistance detection. Allele-Specific Loop-Mediated Isothermal Amplification (AS-LAMP) was evaluated as a possible rapid diagnostic method for acetyl-CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibiting herbicides resistance in Lolium spp. Results: AS-LAMP protocols were set up for the most frequent mutations responsible for herbicide resistance to ALS (positions 197, 376 and 574) and ACCase (positions 1781, 2041 and 2078) inhibitors in previously characterized and genotyped Lolium spp. populations. A validation step on new putative resistant populations gave the overview of a possible use of this tool for herbicide resistance diagnosis in Lolium spp. Regarding the ACCase inhibitor pinoxaden, in more than 65% of the analysed plants, the LAMP assay and genotyping were in keeping, whereas the results were not consistent when ALS inhibitors resistance was considered. Limitations on the use of this technique for herbicide resistance detection in the allogamous Lolium spp. are discussed. Conclusions: The LAMP method used for the detection of target-site resistance in weed species could be applicable with target genes that do not have high genetic variability, such as ACCase gene in Lolium spp.